Is it possible to programmatically create lines in sketch entering start and end points values relative to the internal sketch coordinate system? I tried to record a journal but it was of no use because points there are absolute. Can you please give an advice?
Mapping from the sketch coordinate system to the absolute coordinate system is pretty simple.
Then, if you have a point with coordinates (h,k) in the sketch coordinate system, its absolute coordinates are
sketchOrigin + h*sketchX + k*sketchY
Here, the "*" denotes scalar-vector multiplication, and the "+" is vector addition.
There are functions in both SNAP and NX/Open to do this sort of mapping, too, but it's just as easy to do it from first prnciples.